Anemia is a major health problem in sub-Saharan Africa affecting 35-75% of pregnant women and is an important cause of maternal morbidity and mortality, fetal loss and low birth weight. As part of a strategy to prevent anemia and its adverse effects, the World Health Organization recommends routine use of iron supplementation in all pregnant women living in areas with high prevalence of iron-deficiency. However, there is little evidence showing that this intervention is effective in HIV-infected pregnant women. The major hypotheses in this study are that iron supplementation in HIV-infected pregnant women 1. is ineffective at preventing anemia 2. increases the risk and density of malaria infection 3. leads to increased deposition of iron in the bone marrow 4. increases HIV viral load. Currently, it would be considered unethical to test these hypotheses in a placebo-controlled randomized trial due to the absence of evidence from prior observational studies and the fact that iron supplementation is standard practice. Thus, a cross-sectional study of third trimester HIV-infected pregnant Malawian women will be conducted, in the third trimester, to compare between women who receive iron supplementation and those who do not, the prevalence of maternal anemia, the prevalence and density of malaria parasitemia, concentrations of ferritin, serum Transferrin Receptors (sTFR) and HIV-1 RNA. The correlation between duration of iron supplementation and these outcomes will also be assessed. Results from this study could form the basis for conducting a placebocontrolled randomized clinical trial assessing the detrimental or beneficial effects of iron supplementation in HIV-infected pregnant women or could lead to modifications of the current anti-anemia interventions in HIVinfected pregnant women. [unreadable] [unreadable]